Label dispenser with constant tension means



Dee. 23, 1969 H. DINTER Y 3,485,414

LABEL DISPENSER wm consum Tnnsron MEANS Filed May 13. 1968 5 Sheets-Sheet 1 LABEL DISPENSER WITH CONSTANT TENSION MEANS Filed May 13, 1968 5 Sheets-Sheet 2 J5 .f4 $6.24.? JZ/@55 0 5014,25 J2 Dec. 23, 1969 LBEL DISPENSER WITH CONSTANT TENSION MEANS Filed May 15, 196B 5 Sheets-Sheet 3 United States Patent LABEL DISPENSER WITH CONSTANT TENSION MEANS Herbert Dinter, 1300 S. Shadydale, West Covina, lCalif. 91790 Filed May 13, 1968, Ser. No. 728,611 Int. Cl. B65h 5/28 U.S. Cl. 221--73 21 Claims ABSTRACT OF THE DISCLOSURE A label dispenser for dispensing pressure sensitive labels in succession from a backing strip to a label applicator by endwise movement of the strip about the edge of a thin peeling edge plate which forms the strip into a sharp reverse bend in such away that the strip is effectively peeled from each label. The dispenser is characterized by a novel intermittent feed mechanism for the backing `strip which maintains a constant tension in the strip to prevent parting of the strip during intermittent feeding hereof, and by a novel label sensing unit which is adjustable to assure proper dispensing of each label t the label applicator.

BACKGROUND OF INVENTION 4Field of the invention This invention relates generally to machines for applying pressure sensitive labels to containers and other articles. More particularly, the invention relates t-o an improved label dispenser for dispensing pressure sensitive labels in succession from aibacking strip to a label applicator.

Prior art A variety of machines have been devised for applying pressure sensitive labels to containers or other articles `which are transported in succession past the machine by the conveyor or the like. The present invention is concerned with machines of this type wherein the labels are carried by a backing strip which is fed endwise about the edge of a thin peeling edge plate that forms the strip into a sharp reverse bend in such a way that the strip is effectively peeled from each label at the plate edge. This label dispensing operation is performed by a label dispenser which presents each peeled label to a label applicator. The operation of the label dispenser and label applicator are synchronized with the movement, through a labeling station, of the articles which are to receive the labels in such a way that the dispenser feeds the labels in succession to the applicator and the applicator, in turn, applies the labels to the articles as the latter pass through the station.

The existing label applying machines of'this kind, and particularly their label dispensers, are subject to certain `deficiencies which this invention seeks to cure. One of these deficiencies resides in the fact that the intermittent strip feed mechanism employed in the label dispensers subject the label backing strip to substantial periodic inertia induced tensile stresses which frequently cause parting of the strip. Many of the existing label dispensers are further delicient in that they lack adequate adjustments for accommodating articles of various sizes and shapes and regulating the strip feed mechanism to assure proper dispensing of the labels to the label applicator. Another disadvantage of some existing labeling machines resides in the fact that they are not reversible so as to permit the 3,485,414 Patented Dec. 23, 1969 ICC application of labels to articles moving in either direction past the machines.

SUMMARY OF THE INVENTION The present yinvention provides an improved label dis penser which avoids the above-noted and other drawbacks of the existing label dispensers. According to one of the invention, for example, the strip feed mechanism of the dispenser embodies a novel arrangement of intermittently driven constant speed infeed rolls and continuously driven constant torque outfeed rolls for intermittently feeding the backing strip around the peeling edge plate. This feed roll arrangement is effective to eliminate inertia induced stresses in the backing strip and to maintain a generally constant tension in the strip, whereby parting of the strip during intermittent feeding thereof is avoided. Another feature of the invention resides in a unique label sensing unit for controlling the backing strip travel during each label dispensing cycle of the label dispenser in sucha way as to assure proper dispensing of the labels from the backing strip to the label applicator. To this end, the sensing unit is arranged to generate an electrical control signal in response to arrival of each label at a predetermined position along the infeed path of the backing strip to the peeling edge plate. The control signals from the sensing unit are utilized to control the strip feed mechanism in such manner that each actuation of this mechanism to initiate a label dispensing cycle advances the backing strip the correct distance to bring a label into proper relation to the label applicator for application of the label to an article in label receiving position with respect to the applicator. The label sensing unit is adjustable in a unique -way which permits precise registry of each dispensed label with the label applicator.

According to another important feature of the invention, the various parts of the label dispenser are uniquely arranged to accommodate application of labels to articles travelling in either direction through the labeling station of the labeling machine embodying the dispenser.

` according to the invention;

FIGURE 3 is a side elevation of the label dispenser;`

FIGURE 4 is an enlarged section taken on line 4--4 in FIG. 3; FIGURE 5 is an enlarged section taken on line 5-5 in FIG. 4; FIGURE 6 is a section taken on line 6-6 in FIG. 7; FIGURE 7 is an enlarged section taken on line 7 7 in FIG. 3; and

FIGURE 8 is an enlarged fragmentary perspective detail illustrating the manner in which the backing strip is fed endwise about the peeling edge plate to peel the strip from the labels on the strip. l r According to the present invention, there is provided a label dispenser, represented in the drawings by the label dispenser 10, for dispensing pressure sensitive labels 12 from a backing strip 14 to which the labels are secured in longitudinally spaced relation. In general terms, the label dispenser comprises a frame 16 mounting a thin peeling edge plate 18. This plate has a relatively sharp peeling edge 20 and opposite side faces 22 joining the edge. Also mounted on the frame are feed means 24 for feeding the backing strip 14 endwise along an infeed path 26 leading to the peeling edge plate 1B and an outfeed path 28 leading from the plate. The infeed path 26 extends across the upper "face of the peeling i edge plateias peeling edge plate 18, at the conclusion of a corresponding mal to its peeling edge 20. Ffhe outfeed path 28 extends across the lower face of thevplate, away from and gen erally normal to the edge. From this description, it is evident that during operation of the stripfeed mechanism 24, the backing 4 strip 14 undergoes endwisel movement across the upper face of the peeling `edge plate 18 toward its peeling edge' 20, 'then around this edge, and nally backf across theunderface `of the plateaway'from the peeling edge; Referring'particularly to`F'lG. 8, it'will be observed that the peeling" edgeplate 18 forms the backing strip 14I into a sharp reverse bend as it passes around the peeling edge 20 of the plate in-such a way that the strip is effectively peeled from each label 12 at the edge. This method of peeling a backing strip from pressure sensitive labels on the strip is old in the art and thus need not be explained in detail. Suffice it to say that the peeling occurs by virtue of the fact that the peeled strength of the pressure sensitive adhesive on each label is insufficient to retain the label in adhesive contact with the backing strip as the latter travels around the sharp peeling edge 20. Accordingly, the backing strip is separated from each label with a peeling action, in the manner depicted in FIG. 8, as the strip passes around the peeling edge.

According to one important feature of the invention, the strip feed mechanism 24 includes an infeed friction roller 30 along the infeed path 26 and an outfeed friction roller 32 along the outfeed path 28. Mounted in the frame 16 opposite each roller is a means 34 for urging the backing strip into frictional driving contact with the adjacent roller. Associated with the infeed roller 30 are selectively operable drive means 36 for selectively and intermittently driving this roller at a given constant rim speed and in a direction to feed the backing strip 14 along the infeed path 26 f toward the peeling edge 20 of the peeling edge plate 18. Associated with the outfeed roller 32 are constant torque drive means 38 for driving this roller with a generally constant torque at a maximum rim speed slightly greater than the constant rim speed of the infeed roller 30 and in a direction to feed the backing strip along the outfeed path 28 away from the peeling edge 20.

In the particular embodiment of the invention which has been selected for illustration, the backing strip 14 is initially wound into a supply roll 40. This supply roll is rotatably supported on a spindle 42 mounted on the dispenser frame 16. The backing strip 14 passes from the supply roll to the infeed roller 30 and then along the infeed path 26 to the peeling edge plate 18. The illustrated embodiment of the invention is also equipped with a rotary take-up shaft 44 located along the outfeed path 28 of the backing strip 14 on which the strip is wound after it passes the outfeed roller 32. According to a further feature of the invention, the take-up shaft 44 is driven, by constant torque drive means 46, at a maximum rim speed slightly greater than the maximum rim speed of the outfeed roller 32.

Another feature of the invention is concerned with a label sensing unit 48 which is mounted on the dispenser frame 16, along the backing strip infeed path 26, for sensing passage of the labels 12 past the predetermined position along this path. Embodied within the sensing unit are sensing means 50 for lgenerating an electrical control signal in response to movement of each label 12 through a predetermined position'along the infeed path 26. As noted'earlier and hereinafter explained in more detail, these control signalsv are utilized to control the strip feed mechanism 24 in such a way that the backing strip 14 is advanced a predetermined distance during each intermittent operation of themechanism. A unique feature of the label sensing unit 48.,resides in the fact that the label sensing means 50 are adjustable to effectively adjust the label sensing position of the unit along the infeed path 26 to regulate the position occupied by each dispensed label 12, relative to` the peeling edge 20 of the operating o'rdispensing'cycleof'the dispenser.

Briefly, during operation Iof the label dispenser 10, the infeed roller drive means 36 are inactive, while the outfeed roller drive means 38 and take-up shaft drive means 46 are continuously powered to exert continuous, predetermined 'idrivingtorque on the Outfeed roller 32 and the take-up shaft 44.` Prior to actuation of the infeed roller drive means 36, -therefbre1t he`backing strip 14 remains stationary, and-,the outfeed roller 32 and take-up shaft 44 cooperate `to maintain a predetermined tension in the portion of the backing strip between the infeed roller and the take-up shaft. An operating or label dispensing cycle of Vthe dispenser is initiated by activating the infeed roller drive means to drive the infeed roller 30 at its constant rim speed; Under these'conditions, the backing strip 14 is fed endwise along its infeed path 26 and outfeed path 28,. from the supply roll 40 to take-up shaft 44, by the `con-jointfeeding action of the infeed roller 30, outfeed roller 32, and take-up shaftfDuring this cycle, the outfeed rollerand take-up shaft operate to maintain a constant tension in the portion of the backing strip between the endfeed roller and the take-up shaft because of the differential rim velocities of lthe rollers and shaft. In the course of its periodic endwise movement, the backing strip passes around =the peeling edge'20 of the peeling edge plate18 to eifect dispensing of successive, labels 12 from the strip to a label applicator 51. This label applicator is mounted adjacent the peeling edge plate, as shown. The intermittent operating or label dispensing cycles of the machine are initiated by actuation of an article sensing device (not shown): in response to movement past the applicator 51 of the articles (not shown) which are to receive the labels. During each cycle, the label dispenser 10 presents one or more labels 12 to the label applicator 51 which then applies the labels to the passing articles.

The number of labels dispensed during each cycle is determined by the travel of the backing strip 14 around the peeling edge plate 18. This endwise travel of the backing strip, in turn, is controlled jointly by the label sensing unit 48 and an electrical control unit 452 having numbered buttons 54. These buttons may be selectively depressed to conditions or preset the label dispenser for dispensing one, two or three labels during-each dispensing cycle. The label sensing unit 48, Control unit 52, and the article sensing device are interconnected in such a way that the dispenser is actuatedto initiate a label dispensing cycle in response to movement of each article past the label applicator. Each dispensing cycle is terminated in response to the electrical control signals generated by movement past the label sensing unit 48 of the number of labels for which the dispenser has been preset by depression of the control buttons 54. The label sensing unit 48 is adjusted in such a way that during each label dispensing cycle, the backing strip 14 is advanced to a posiiton in which the next label to be dispensed remains adhesively attached at its extreme trailing edge to the backing strip and projects laterally beyond-the peeling edge 20 of the peeling edge plate 18 into label applying relation to the label applicator S1, in the manner illustrated in FIG. 1. i

Referring now in the greater detail to the illustrated embodiment of the invention, the dispenser frame 16 has a generally cylindrical housing 56 which is open at its front end, as the housing is viewed in FIG. l. The rear end of this housing is closed by an end wall 58. Housing l S6 is cut away at its top to form a circumferentially extending opening or slot 60; This slot opens through the front edge of the housing, as shown. The backing'strip supply roll 40 is concentrically positioned within the cylindrical dispenser housing 56 and is rotatably supported 0n the spindle 42 in the manner best illustrated in FIGS; 1 and 3. Spindle 42 comprises a hollow tube, the rear end of which is rigidly joined to the rear housingwall 58.

Supply roll 40` is placed on the spindle42 through the open front end of the housing 56 and is retained in positionon the spindle by a collar 62 on the spindle. Collar `62 has lateral arms 64 with spring load friction tips 66 which seat against the inner wall of the housing 56 to releasably retain the collar on the spindle.

Label dispenser is supported on the main frame of the overall labeling machine in any convenient way. In this instance, the dispenser is supported by a bracket `68 on the frame having a shaft 70` which ts slidably within the tubular supply roll spindle 42. Means (not shown), such as a lock screw, are provided for securing the dispenser to the bracket shaft 70.

The backing strip drive mechanism 24 has a housing 72 including an annular Wall 74 of generally elipsoidal shape closed at itsends by end Walls 76 and 78. This drive housing is positioned on top of the cylindrical dispenser lhousing 56, just to the rear of the dispenser housing slot `60, with the annular Wall 74 of the drive housing seating against an upper mounting flange 80 on the dispenser housing. The ends of the drive housing extend laterally of the dispenser housing, as shown. The driving housing is releasably secured to the dispenser housing by bolts 82.

`Referring particularly to FIGS. 6 and 7, it will be seen that the backing strip infeed roller 30, outfeed roller 32, and take-up shaft 44 extend forwardly from the drive housing 72 in laterally spaced parallel relation toone another and the axis of the dispenser housing 56. The rollers and shaft are located adjacent to the left end, center, and right end, respectively, of the drive housing as the latter is viewed in thedrawings. The infeed roller 30 is` a resilient friction roller having a rear shaft 84 which is rotatably supported in the driving housing 72. Similarly, the outfeed roller 32 is a friction roller having a rear Vshaft 86 rotatably supported in the drive housing. Similarly, thel take-up shaft 44 has a rear shaft portion 88 rotatably supported in the drive housing. `The infeed roller 30, outfeed roller 32, and take-up shaft 44 are driven by a common drive motor 90 within the drive housing 472, This drive motor thus forms part of theinfeed roller drive means 36, the outfeed roller drive means 38, and the take-up shaft drive means 46. h v In` addition to the motor 90, lthe infeed roller drive means 36 has a driving sprocket 92 rigid on the motor shaft. Trained about this sprocket and a sprocket 94 rotatable on the infeed roller shaft 84 is a sprocket chain 96.` Also embodied in the infeed roller drive means 36 is an electromagneticclutoh 98 for drivably connecting the driven sprocket 94 to the infeed roller shaft 84. This clutch is normally disengaged topermitcontinuous operation of .the` motor 90 without driving the infeed roller 30. The clutch is engaged by energizing its coil 98 to drivably couple thedriven sprocket 94 to the infeed roller shaft 484. The infeed roller30ris then directly coupled to the motor` 90 `for rotation at, a predetermined constant speed by themotor. j

"Theoutfeed roller drive means 38 -includes a second driving sprocket100 rigid on the motor shaft. Trained about `the sprocket 100 and a driven sprocket 1.02 rotatable on the outfeed roller shaft 86 is `a` sprocket chain 104L Driven sprocket 102 is drivably coupled to the outfeed 4roller shaft 86 through a spring loaded slip clutch 106. The outfeedroller 32 is thus subjected to a continuous driving torque-solong` as the motor 90 is energized. The spring loading of the slip clutch k106 is adjusted to permitvslippage of the clutch plates 108 in response to a predetermined l:restraining `torque on the outfeed roller 32. Accordingly, the outfeed `roller drive'means 38` constitutes a constant torque drive means which exert a predetermined driving torque on the outfeed roller 32 solong as the motor 90` is energized.

The take-up shaft drive means 46 has a spring drive belt 110 whichis trained about pulleys 112 and 114 fixed to the rear ends of the outfeed roller shaft 86 and the rear shaft portion 88 of the take-up shaft 44. Thus, the take-up shaft is driven from the motor through the outfeed roller slip clutch 106 and the outfeed roller shaft 86. The tension in the spring drive belt is adjusted to permit slippage of the belt in response to a predetermined restraining torque on the take-up shaft 44. It will be understood, therefore, that the take-up shaft drive means 46 also constitutes a constant torque drive means which exert a continuous constant driving torque on the takeup shaft 44 during rotation of the outfeed roller shaft 86.

It is evident from the preceding description of the backing strip feed mechanism 24 that the infeed roller 30. is positively driven at a constant speed when its clutch 96 is engaged with the motor 90 energized. The outfeed roller 32 and take-up shaft 44, on the other hand, are arranged to be continuously drivenwith a constant torque and at given maximum speeds so long as the motor is energized. According to an important feature of the invention, the ratio of the speed reducer embodied in the drive motor 90, and the ratios of the dispenser drive means 36, 38, and 46 are such that the maximum rim speed of the outfeed roller 32 is slightly greater than the constant rim speed of the infeed roller 30, and the maximum rim speed of the take-up shaft 44 is slightly greater than the maximum rim speed of the outfeed roller.

As noted earlier, each feed roller 30, 32 has an adjacent pressure means 34 for urging the backing 'strip 14 lin frictional driving contact with the adjacent roller. In this instance, the pressure means comprise idler or pressure rollers located opposite and parallel to their respective feed rollers. The infeed roller 30 and its pressure roller 34 straddle the infeed path 26 of the backing strip 14, while the outfeed roller 32 and its pressure roller 34 straddle the outfeed path 281 of the strip. Pressure rollers 34 are mounted on and extend forwardly from an equalizer plate 116. This equalizer plate seats slidably against the front wall 76 of the drive housing 72 and is pivotally suspended at its center on an eccentric shaft 118 journaled in the drive housing 72. Fixed to the rear end of the eccentric shaft 118 is a lever 120 by which the shaft may be turned to elevate and lower the equalizer plate 116. The eccentric shaft 118 is constructed and oriented in such fashion that rotation of its lever 120 in one direction elevates the equalizer plate 116 and thereby the pressure rollers 34 to a position wherein these rollers are disposed to urge the backing strip 14 into frictional driving contact with their respective feed r-ollers 30, 32. Rotation of the lever 120 in the opposite direction lowers the equalizer plate 116 and pressure rollers 34 to positions wherein these rollers are spaced from the feed rollers 30, 32 to permit insertion and retraction of the backing strip into and from the space between the rollers.

As noted earlier, the label dispenser 10 has an electrical control unit 52. This unit is removably mounted by screws 122 within an upper opening 124 in the drive housing 72. Formed in the underside of this housing is a second opening 126 in which the control unit may be `alternatively installed, as described later. i l i Turning now to FIGS. l through 5, it will be seen that the label sen-sing unit 48 has a generally cylindrical housing-126 Vwhich contains the label sensingmeans 50. The sensor housing 126 has a cylindrical wall 128 closed by end walls 130. The label sensing means 50 comprises a pair of coaxial Shafts which are rotatably supported in an restrained against axial movement relative to the sensor housing end walls 130. Positioned between and secured to the inner ends of these shafts is a detector`136, in this instance a photo-electric detector. Detector 136 has a housing 138 extending through which, on yan axis normal to and intersecting the common axis of the support shafts 132, 134, is a light passage 140. The right hand or front end of this passage in FIG. is open and registers with a circumferential slot 142 in the sensor housing 126. Mounted Within the left hand or rear end of the light housing 138 is a photosensitive cell 144, referred to herein simply as a photo cell. A translucent or frosted glass plate 146 is interposed in the light passage 140 between the photo cell 4and the front end of the passage. A lens 148 is positioned -within the front end of the passage.

Fixed on the rear detector support shaft 34 is a collar 150 to which is attached one arm of an L-shaped lamp support bracket 152. The bracket arm extends radially from the collar and through a second circumferential slot 154 in the sensor housing 12-6. The second arm of the lamp bracket 152 is located externally of the housing 126 and extends parallel to the housing axis toward the first housing slot 142. Mounted on the end of the outer Ibracket arm is a lamp housing 156 which extends parallel to and is radially spaced from the sensor housing ,126. Positioned within the lamp housing is a lamp 158. Lamp housing 156 has an illumination port 160 located on the axis of and opening toward the front end of the light passage 140 in the detector housing 138. It will be understood, therefore, that light from the lamp 158 passes through the port 160, the `slot 142 in the `sensor housing 126, and the light passage 140 in the detector housing 138 to the detector photo cell 144. The detector 136 `and lamp housing 156, both being fixed to the detector support shafts 132, 134, rotate in unison when these shafts are turned, whereby the lamp housing port |160 remains in coaxial alignment with the detector `light passage 140. Fixed to the outer end of the front detector support shaft 132 is a knob 162 by which the photosensitive detector 136 and the lamp housing 156 may thus be rotated in unison. If desired, the knob and the adjacent sensor housing end wall 130 may be provided -With angular scale markings, as shown, for reasons which become evident shortly.

The rear end wall 130 on the housing 126 of the label sensing unit 48 has an integral coaxial, internally threaded boss 164 which seats against the outer end of a telescopically adjustable sensing unit support `arm 166. A Iscrew 168 extends through the arm and is threaded in the boss 164 for adjustably securing the label sensing unit 48 to the arm. As explained below, the screw 168 may be loosened to permit rotation of the sensor housing 126 relative to the support arm 166. Support arm 166 has inner and outer telescoping sections |170 and 171. The label sensing unit 48 is secured to the outer `arm section 168. The inner arm section 170 extends radially through a circumferential slot 172 in the cylindrical dispenser housing 56 and is journaled at its inner end on the rear end of the housing spindle 42. The support arm 166, and hence the label sensing unit 48, may thus be angularly adjusted relative to the dispenser housing 56 about the housing axis. As indicated in full and broken lines in FIG. 3, the housing slot 172 is such `as to permit angular ad justment of the arm 166 and label sensin-g unit 48 through an 4angle of about 45-degrees to either side of a vertical plane containing the central axis of the dispenser housing 56. Within the dispenser housing 56, the label sensor support arm 166 mounts a curved plate 174 carrying thumbscrews 176 which may be tightened against the housing to secure the arm, and hence the label sensing unit 48, in fixed angular position. The outer arm section 168 may also be telescopically adjusted relative to the inner arm section 170 to adjust the label sensing unit 48 radially of the dispenser housing 56. The arm sections are locked in adjusted position by means of a set screw 178.

At this point, it is significant to observe that the label sensing unit 48 extends parallel to and is radially spaced from the cylindrical dispenser housing 56. Moreover, the label sensing unit is aligned, circumferentially of the dispenser housing, with the infeed roller 30, outfeed roller 32, and take-up shaft 44.

Interposed between the rear wall 130 of the sensor housing 126 and the outer section 168 ofthe support arm 166 is a bracket plate .170 which fits rotatably on the threaded boss 164 of the sensor housing. The peeling edge plate 18 is disposed with one longitudinal edge portion of the plate seating against the outer edge of the bracket plate 170 and is releasably secured to the flange by screws 172. Along the opposite longitudinal edge portion of the peeling edge plate are a set of holes 174 for alternatively receiving the screws 172, whereby the position of the plate may be reversed, as explained below. Thus, the bracket plate 170 constitutes, in effect, a rnounting flange on the peeling edge plate 18. This mounting flange is clamped between the rear end wall 130 of the sensor housing 126 and the outer end of the support arm 166 when the housing clamp screw 168 is tightened. Thus, the screw 168 is effective to secure the peeling edge plate 18 and the label sensing unit 48 in fixed position relative to the support arm 166.

The peeling edge plate 18 is a relatively thin metal plate, one edge of which forms the peeling edge 20. This peeling edge extends parallel to the longitudinal axis of the label sensing unit 48. The opposite edge portion of the plate turns toward the dispenser housing 56, as shown best in FIG. 2, for reasons which 4will appear presently.

The label dispenser 10 is conditioned for operation by first removing the spindle collar 62 and placing a supply roll 40 of labels 12 and their backing strip 14 on the spindle. The collar is then replaced to retain the supply roll on the spindle. The lever 120 is now rotated to retract the pressure rollers 34 from their respective feed rollers 30, 32 and the leading end of the backing strip 14 is threaded through the dispenser, in the manner illustrated best in FIGS. 1 and 3, whereby the backing strip conforms to its infeed and outfeed paths 26, 28. In this regard, it will be observed that the backing strip passes along its infeed path 26 from the supply roll 40 upwardly through the dispenser housing slot 60, then between the infeed roller 30 and its pressure roller 34, then downwardly around the dispenser housing 56 and the housing 126 of the label dispensing unit 48, then between the latter housing and the peeling edge plate 18, and linally across the upper face 22 of the plate to its peeling edge 20. From this point, the strip passes around the peeling edge in a sharp reverse bend and along its outfeed path 28, from the peeling edge, across the underside of the peeling edge plate 18, then upwardly around the dispenser housing 56, and then between the outfeed roller 32 and its pressure roller 34 to the take-up shaft 44. The leading edge of the backing strip is secured to the take-up shaft in any convenient way. Strip guides 176 may be adjustably mounted on the dispenser housing 56 between the infeed roller 30 and the label sensing unit 48, as shown. After the backing strip has been thus properly threaded through the dispenser, the lever 120 is returned to its initial position to urge the strip into feeding contact with the infeed and outfeed rollers 30, 32.

During actual operation of the label dispenser 10, the motor is continuously energized to exert constant driving torque on the outfeed roller 32 and the take-up shaft 44. The infeed roller remains stationary until its clutch coil 98 is energized. Under these conditions, the outfeed roller drive means 38 and the take-up shaft drive means 46 slip to maintain constant driving torque on the outfeed roller and take-up shaft and, thereby, constant tension in the backing strip 14. When the infeed roller clutch 96 is engaged by energizing of its clutch coil 98, the infeed roller 30 is driven at constant speed. The backing strip 14 is thereby fed endwise at constant speed from the supply roll 40, around the peeling edge 20, to the take-up shaft 44 in such a way that the backing strip remains under constant tension. As the backin g strip travels around the peeling edge, the strip is peeled from the labels 12, in the manner explained earlier and illustrated in FIGURES l and 8.

As the backing strip 14 moves along its infeed path 26 from the infeed roller 30 to the peeling edge 20, the strip passes around the label sensing unit 48 and between the front end of its photo detector light passage 140 and the external lamp 158. The labels 12 and backing strip 14 are translucent but have different light transmission characteristics. Accordingly, periodic movement of the labels between the light passage and lamp causes the photo cell 144 to generate a fluctuating electrical control signal. This control signal is fed to the control unit 52 and serves to actuae this unit in such a way as to de-energize the infeed roller clutch coil 98 when the label 12 currently passing the label sensing unit 48 is situated in centered relation relative to the sensitive axis of the unit, that is the axis of the detector lens 148.

t `At this point, attention is directed to a unique and highly beneficial feature of the label sensing unit 48, wherebythe latter is capable of accurately sensing arrival of each label 12 at a center position on the sensitive axis of the `sensing unit. According to this feature, the lens 148 is 'focused to produce on the frosted glass plate 146 a slightly out of focus or fuzzy image of each label as the latter passes between the lens and the light source 158. This image occupies a major portion or substantially entire. area of the plate, within the field of view of the photocell 144, when the label is centered on the sensitive axis. If the label is slightly displaced from the sensitive axis in either longitudinal direction of the backing strip 14, the label imageoccupies only a portion of a glass plate within the field of view of the photocell. Under these conditions, the remainder of the glass plate is illuminated by the light which passes through the portion of the backing strip between the `respective label and the adjacentlabel. Accordingly, as each label 12 moves past thelabel sensing unit 48, the intensity of light incident on the photocell 144 `initially diminishes as the label approaches its center position on the sensitive axis of the unit and then `increases as the label recedes from this position. The photocell thus receives minimum light when each label is centered on the axis. The control unit 52 is set to respond to this minimum light condition by deenergizing the clutch coil 98, as just explained. As a consequence, the label sensing unit is effective to accurately sense `the position of the labels 12 on the sensitive axis of the unit regardless of legends or other copy imprinted on the labels. In this regard, the present label sensing unit-differs from the existing label sensing units which respond to or sense dark or light areas on the individual labels themselves. Theprimary advantage of the present label sensing unit resides in A its substantially improved sensing accuracy. The present sensing unit, for example, is sufficiently sensitive to control or sense the position of the labels within an error on the order of .010 inch.

" As noted: earlier, periodic operation of the label dispenser 10 is triggered by movement, past the label applicator 51, of the articles which are to receive the labels from the applicator. Each time the'label dispenser is thus triggered, its infeed roller clutchy 96 is momentarily engaged to drive the infeed roller and thereby effect endwise `feeding movement of the backing strip 14. The backing strip,v continues to be advanced until the number of labels,rcorresponding to the depressed control button 54 of ther control unit 52, have been dispensed to the label applicator 51.` At this point, the control signal from the label 4sensing unit 48actuates the control unit 52 to delenergize` the infeed clutch coil 98 and thereby terminate endwise feeding of the backing strip in the position wherein the next label 12 projects beyondf the peelingedge Z0 into label applying relation to the label applicator 51, with the trailing edge of the label stilladhesively attached tothe backing strip 14, in the manner illustrated in FIG- URES l and 8. The terminal position occupied by the backing strip 14 at the conclusion of each such label dispensing is adjusted by. angular adjustment of the label sensing means within the sensor housing 126. In this regard, it will be recalled that the label sensing means 50 are rotatable by means of the knob 162. 'Ihis rotation of the label sensing means obivously shifts the point of intersection of the infeed path 26 by the sensitive axis A of the label sensing means 50 lengthwise of this path. This endwise adjustment of the sensitive axis along the infeed path, in turn, obviously adjusts the position occupied by the backing strip 14 along its infeed path at the conclusion of each label dispensing cycle. The actual electrical connections of the label dispenser and the internal circuitry of the electrical control unit 52 form no part of the invention and, accordingly, have not been illustrated nor will they be described in detail. After all of the labels 12 have been peeled from the backing -strip 14, the entire length of the strip will be wound on the take-up shaft 44. The iinal step in the operation of the label dispenser 10, therefore, involves removal of this rolled strip from the take-up shaft and reconditioning of the dispenser for operation by placement of a new supply roll 40 on the dispenser spindle 42.

The present label dispenser has several unique and highly important features of construction and operation. One imortant feature of the dispenser, for example, resides in the fact that the strip lfeed mechanism 24 is effective to maintain a constant tension in the backing strip 14 and to eliminate inertia induced stresses or loads in the strip as occur in the intermittent strip feed mechanisms of the existing label dispensers. This maintenance of a constant tension and elimination of inertia induced stresses in the backing strip prevents the latter from parting or breaking during operation of the dispenser, as frequently occurs in the existing machines of this type.

Another important feature of the invention resides in the adjustability of the label dispenser. In this regard, for example, it has already been noted that the peeling edge plate 18 and label sensing unit 48 maj,r be adjusted relative to the dispenser housing 56, both angularly about the aixs of the housing and radially toward and away from the housing. These adjustments permit the effective elevation of the peeling edge plate and the label sensing unit to be adjusted, as indicated in FIGURE 3, thus to accommodate lapplication of labels to articles of various sizes and shapes. In this regard, it will be observed in FIGURE 3 that the label applicator S1 is vertically adjusted with the peeling edge plate and label sensing unit.

The present label dispenser may be also adjusted to accommodate application of the labels 12 to articles moving in either direction past the dispenser. The flow lines in FIGURE 3, for example, illustrate the dispenser when set for articles which move from right to left past the dispenser. The broken lines, on the other hand, illustrate the dispenser when set to accommodate articles which move from left to right past the dispenser. It will be observed that adjustment of the dispenser from its full line condition to its broken line condition and vice versa involves removal of the control unit 52 from the drive housing 72, inversion of the drive housing relative to the dispenser housing 56, and remounting of the control unit in the currently upper side wall opening 124, 126 of the drive housing. The adjustment further involves swinging of the label sensing unit 48 between its full and broken line positions in FIGURE 3, rotation of the label sensing unit on its central axis so that the unit housing slots 142, 154 face the backing strip 14, and mounting of the peeling plate edge 18` in the appropriate position on the label sensing unit so that the peeling edge 20 of the plate extends in the direction of; movement of the articles past the dispenser, all asv illustrated in FIGURE 3.

A further important feature of the invention resides in the fact that the take-up shaft 44 may be hollow, as shown, to permit air tlow through this: shaft.

While the invention has been described in what is presently conceived to ge one of its most practical embodiments, it will be evident to those versed in the art that variousmodifications of the invention are possible.

the intersection of said axis with said infeed path in the lengthwise direction of said infeed path. 8. In a label dispenser for dispensing pressure sensitive labels in succession from a backing strip to which said labels are secured in longitudinally spaced relation, the

What is claimed is:

1. In a label dispenser for dispensing pressure sensitive labels in succession from a backing strip to which said labels are secured in longitudinally spaced relation, the combination comprising:

a frame,

a thin peeling edge plate mounted on said frame having a relatively sharp peeling edge, and opposite side faces joining said edge,

a stii'p feed mechanism on said frame for feeding said combination comprising:

a frame, a thin peeling edge plate mounted on said frame having a relatively sharp peeling edge and opposite side faces intersecting said edge,

hacking striP endWise along an infeed Path extending l a strip feed mechanism mounted on said frame for across one face ot sa1d Plate toward and generally feeding said backing strip endwise along an infeed notinal to Said Peeling edge tnen around Said Peel path extending across one face of said plate toward ing edge, and finally along an ontfeed Path extending and generally normal to said peeling edge, then across the other face of said Plate aWay trorn said around said peeling edge, and finally along an outfeed peeling edge, whereby said strip is formed into asharp path extending across the other face of Said Piate reverse bend as it passes around said peeling edge in away from said peeiing edge, whereby said strip is Sitlon gay inatsaid Strip is peeled tioin eaen label formed into a sharp reverse bend as it passes around a sai e ge, an sai said feed mechanism including an infeed friction roller 2O peeelgtl eegle iesiutlsidwlgltnald smp 1S along said infeed path, an oiitteed friction loller a label sensing unit mounted on said frame along said along sa1d outfeed path, pressure means opposite each infeed path adjacent Said peeling edge in such a Way feed roller for urging said backing strip into frictional that Said backing Strip passes around said sensing driving contact with the adjacent feed roller, selecunit as Said Strip travels along said infeed path to llvely opeleble eellstallt Speell dllve. lllealls for selec' 25 said peeling edge, said sensing unit having a sensivglvlllelillgilldlfffi iiieeeixigaigfininiiiyigifein;Sig; leiicllgflatltlll iilellllsll Seeing garage @i each, iaiji aciessaid tniitivi driving said outfeed roller with a generally constant nnmellrnsboglt E eil/gis igfaallltsltnnelnorni iii31alcsaanniueltpilli le igcigiiigSggiijivgngxriii igetiirgcigg; ifngagi i nbiilmesilp eaollg sa1d ontleed path and away movement of said backing stripalong .said infeed 2. The comblinatio aco'rding to claim 1 including: 3f pietll .helebi/.to adinet .tltlle peslllol lf lllellseetllll a take-up shaft mounted on said frame along said outo gndevise lelrlltlill lfllssail'lttnfesed ,lhee pa lll t e feed path and following said outfeed roller, 9 Th b. t. d. e tp l 8 h means for securing the leading end of said backing strip .d'1 eieolll. llla loll accor .lng o e almtt W elell.' l to Said take up shaft, and saih abe sensing unit coiilpijiss a genera y cyliii1 tlica constant torque drive means for driving said take-up 40 .Ollslng eolltlllllllg Sal. ede Selleltllg lllallsell f a2;- shaft with a generally constant torque and at a maxilng e' centre exls eelllel ent Wlt Sal axle o a mum speed slightly greater than the maximum rim .illslmellt of Seld label Sellslllg lllealls speed of said outfeed roller to wind said strip on salll label sellslllg menne. eolllpllsee e photosellsltlve said take up Shaft detector mounted within said hous ing for rotation 3. The combination according to claim 1 including: lelatlve to Seld llouslllg .on Sald axle of adlustment a label sensing unit mounted on said frame along said and for sensing ,light incident on said detector along infeed path for `sensing passage of each label past a Sald eensltlveaxls a llgllt soulee mollllted elleemlllly given Position along saidinfeed path' of said housing on said sensitive axis for directing 4. The combination according to claim 3 wherein: nglit towni'd sadnetootoi along Sao Sensitive axis said sensing unit has a sensitive axis extending transsaidhonsing having a cltcumferential slot on said Versely of and intersecting said infeed path, and said sensitive axis tnioilgn Wnienlignt troni Said soiiiee unit includes label sensing means responsive to pas- Passes to sain detector Said infeefi Patn Passliig be' sage of said label across said sensitive axis, and means tween Said light Source and noiising Wnei'eby iignt for adjusting said sensing means to adjust the intertroni Said s oliree Passes to Salti detector throiigh said section of said axis with said infeed path in the bat-kms Strlpiand means operatively C Onnectlng sa1d lengthwise directieI1 of said infeed path' 55 detector and light source for unified adjustment there- 5. The combination according to claim 1 including: ot about said axis of adinstnientto Vary said POSitlOn means on said frame along said infeed path in advance ot intersection iengthwise of said infeed Pathof said infeed roller for rotatably supporting a supply 10; The combination according to claiin 9 Wherein i011 of said backing Strip and1abe1s said means operatively connecting said detector and 6. The combination according to claim 1 including: GO light soniee eoinPnseSa generally L'SnaPed. bracket a label sensing unit mounted on said peeling edge plate hai/ing one arIn eXtending radially 0f said adlllstment for sensing passage of each label past a given posi axis through a second circumferentiabslotun said tion along said infeed path adjacent said peeling edge, housing and operatively connected Within Sald hOnS- and ing to said detector and a second arm located exmeans mounting said peeling edge plate and sensing unit ternally ot said housing and extending axially thereof for unified adjustment of said plate and unit relative toward said iirst mentioned slot, and a lamp secured to said frame along a direction line transverse to said t0 the end of said eXternal arm and lOCated 0n Said faces of said peeling edge plate, thereby to vary the sensitive aXiS- i elevation of said plate and unit, 11. In a label dispenser for dispensing pressure sensi- 7. The combination according to claim 6 wherein; 70 tive labels in succession from a backing strip to which said said label sensing unit has a sensitive axis extending labels are secured in longitudinally spaced relation, the

transversely of and intersecting said infeed path, and COIIlbiIlatiOn COmprSingl said sensing unit includes label sensing means respona frame, sive to passage of each label across said sensitive axis, a spindle on said frame for rotatably supporting a supand means for adjusting said sensing means to adjust ply roll of said labels and backing strip,

means `supporting"said plate dn said frame,

a strip feed r mechanism -lon Said frame for intermittently fedingsaid backing'strip endwise along an infeed path extending from said supply roll across one face of` said plate towardfandgenerally normal to saidpeeling"edge,= then `a"rou`nd^` said edge, and finally along an outfeed pathr-extending across the other face of said plate away from said peeling edge, whereby said backing strip is. formed into a sharp reverse bend as it passes around said peeling edge in such a way that said strip, is peeled from each label at said edge, and said feed mechanism including an infeed friction roller mounted ony said frame along said infeed path with its axis parallel to said spindle axis, an outfeed friction roller mounted on said frame along said outfeed path with it's axis parallel to said spindle axis, means opposite eachffeed roller for urging said backing strip into frictional driving contact with the adjacent feed roller, selectively oper able constant speed drive means for selectively and intermittently driving said infeed roller at a given constant rim speed and in a direction to feed said backing strip along said infeed path -from said supply roll toward said peeling edgeand constant torque drive means for continuously driving said outfeed roller with a generally constant torque and at a maximum rim speed slightly greater than the constant rim speed of said infeed roller-in a direction to feed said backing strip along said outfeed path away from said peeling edge.

12. The combination according to claim 11 wherein:

said strip feed mechanism further comprises a take-up shaft mounted on said frame along said outfeed path following said outfeed roller withV 4the axis of said shaft parallel to said spindle axis, means for securing the leading end of said backing strip to said take-up shaft, and constant torque drive means for driving said take-up shaft with a generally constant torque at a maximum rim speed slightly greater than the maximum rim speed of said outfeed roller to wind said backing strip on said take-up shaft.

13. The combination according to claim 12 wherein:

said drive mechanism further comprises a common drive motor for said feed rollers and take-up shaft,

said infeed roller drive means comprises a selectively engageable positive drive clutch for selectively connecting said motor to said infeed roller,

said outfeed roller drive means comprises a slip clutch drivably connecting said motor to said outfeed roller, and

said take-up shaft drive means comprises a slip clutch drivably connecting said outfeed roller to said takeup shaft. ,e

14. The combination according to claim 11 wherein:

said means supporting said peeling edge plate on said frame comprises an arm journale'd` on said spindle, whereby said plate may be rotatably adjusted about the axis of said spindle, and means securing said plate to said arm for angular adjustment of said plate relative to said arm about an axis parallel to said spindle axis.

15. The combination according to claim 14 including:

a label sensing unit mounted on said arm for angular adjustment about said plate adjustment axis in such a way that said backing strip passes from said infeed roller around said sensing unit to said peeling edge, and

said label sensing unit having a sensitive axis extending laterally of said plate adjustment axis and intersecting said infeed path and including label sensing means for sensing passage of each label across said sensitive axis, and means for angularly adjusting said 14 label sensing vmeansV about said plate adjustment axis f to adjust the position of intersection of said'sensitive axis'vvith said infeed path inthe lengthwise direction of said infeed path.`

16. The combination according to claim 15 wherein:

said frame `comprises a cylindrical housing concentrically surrounding said spindle,

said feed rollers and peeling edge plate are located externally of said housing and said housing has a slot through which saidbacking strip is. adapted to extend from said supply roll to said infeed roller, and

said drive mechanism comprises a drive housing supporting said feed rollers, a motorI within said drive housing for driving said feed rollers, and means releasably securing said drive housing to said cylindrical dispenser housing, whereby said drive housing may be mounted in an inverted position on said dispenser housing, and

said means supporting said peeling edge plate on said frame comprises an arm rotatably supported at one end on said frame for angular adjustment about the axis of said spindle, and means securing said plate to the other end of said arm for angular adjustment about an axis parallel to said spindle axis.

17. The combination according to claim 16 including:

a label sensing unit mounted on said arm for angular adjustment about said plate adjustment axis in such a way that said backing strip passes from said infeed roller, around said label sensing unit, to said peeling edge, and

said label sensing unit having a sensitive axis extending laterally of said plate adjustment axis and intersecting said infeed path, and including label sensing means for sensing passage of each label across said sensitive axis, and means for rotatably adjusting said label sensing means about said plate adjustment axis to adjust the position of intersection of said sensitive axis lengthwise of said infeed path..

18. The combination according to claim 17 wherein:

said strip drive mechanism further comprises a takeup shaft rotatably supported on said drive housing parallel to said feed rollers and located along said outfeed path following said outfeed rollers, and constant torque drive means for driving said take-up shaft with a constant torque at a maximum rim speed slightly greater than the maximum rim speed of said outfeed roller, and means of securing the leading edge of said backing strip to said take-up shaft, whereby said backing strip is wound on said take-up shaft.

19. The combination according to claim 18 wherein:

the drive mechanism further comprises a common drive motor for said feed rollers and take-up shaft, and means mounting said motor in said drive housing, and

said infeed roller drive means comprises a selectively engageable positive drive clutch for selectively drivably connecting said motor to said infeed roller,

said outfeed roller drive means comprises a slip clutch drivably connecting said motor to said outfeed roller, and

said take-up shaft drive means comprises a slip clutch drivably connecting said outfeed roller to said takeup shaft.

20. A label sensing unit for sensing labels secured in spaced relation along a translucent backing strip which is fed endwise along a given path of movement, said unit comprising: a photocell and a light source located at opposite sides of said path on an axis intersecting said path, a lens on said axis between said path and photocell, a translucent plate on said axis between said lens and photocell, and

said lens being focused to produce on said plate a References Cited slightly out of focus image vof each label illuminated by said light source as the label passes between said UNITED STTES PATENTS light Source and lens. y 3,379,321 4/1968 Weir A221-73 X 21. A label sensing unit according to claim 20 wherein 5 said labels are translucent, and .FOREIGN PATENTS the light incident on said photocell progressively di- 741,406 11/1955 Great Britain.

minishes as each label approaches a centered posi- I tion on said axis and progressively increases as the STANLEY H- TOLLBERG, Primary EXaminel respective label recedes from said center position. 10 

